.main-header {
  position: relative;
  height: 60px;
  background: rgba(0, 24, 51, 0.9);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
  padding: 0 24px;
}

.header-left {
  display: flex;
  align-items: center;
}

.logo-img {
  height: 36px;
  width: auto;
}

.header-center {
  flex: 1;
  display: flex;
  justify-content: center;
}

.nav-links {
  display: flex;
  gap: 8px;
  padding: 4px;
  background: rgba(0, 36, 77, 0.5);
  border-radius: 4px;
  border: 1px solid rgba(0, 180, 255, 0.2);
  height: 100%;
}

.nav-link {
  color: #fff;
  text-decoration: none;
  font-size: 14px;
  padding: 6px 24px;
  border-radius: 2px;
  transition: all 0.3s ease;
  position: relative;
  cursor: pointer;
}

.nav-link:hover {
  background: rgba(0, 180, 255, 0.1);
}

.nav-link.active {
  background: rgba(0, 180, 255, 0.2);
  color: #00b4ff;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 16px;
  height: 100%;
}

.help-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  background: transparent;
  border: 1px solid rgba(0, 180, 255, 0.3);
  color: #fff;
  padding: 4px 12px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 14px;
  transition: all 0.3s ease;
}

.help-btn:hover {
  background: rgba(0, 180, 255, 0.1);
  border-color: #00b4ff;
}

.user-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  overflow: hidden;
  border: 2px solid rgba(0, 180, 255, 0.3);
}

.user-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.header-decoration {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 4px;
  overflow: hidden;
}

.decoration-line {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 100%;
  background: linear-gradient(90deg, 
    transparent 0%,
    rgba(0, 180, 255, 0.3) 25%,
    rgba(0, 180, 255, 0.6) 50%,
    rgba(0, 180, 255, 0.3) 75%,
    transparent 100%
  );
  box-shadow: 0 0 10px rgba(0, 180, 255, 0.4);
}
